My Grandmother's Bake Chiffon Cupcakes

Ingredients

• 1 cup (125g) all-purpose flour
• 1 cup (200g) granulated sugar
• 1 tsp baking powder
• 1/2 tsp salt
• 1/4 cup (60ml) vegetable oil
• 1/2 cup (120ml) milk, room temperature
• 1 tsp vanilla extract
• 4 large eggs, separated
• 1/4 tsp cream of tartar (for egg whites)
• 1 cup (240ml) heavy whipping cream (optional for frosting)
• 2 tbsp powdered sugar (optional for frosting)
• 1 tsp vanilla extract (optional for frosting)